With the rapid development of display technology, display devices are increasingly widely applied, such as mobile phones, laptops, TVs, onboard displays and electronic tag displays used in supermarkets. However, the display device usually uses a liquid crystal display (LCD) which needs a backlight for liquid crystal display, and the use of backlight results in high power consumption of the display device during display. In order to decrease the power consumption during display, an electrochromic display (ECD) is introduced and widely applied. Electrochromism (EC) is the special phenomenon in which some materials produce a reversible change between a low transmittance chromatic state and a high transmittance achromatic state under the action of an external electric field.
Currently, electrochromic devices (ECDs) manufactured on the basis of the EC technology have been widely used in the fields like lighting control of intelligent buildings, large area outdoor digital and graphic display, vehicle reflectivity adjustable rearview mirrors and aircraft discoloration windows. A conventional ECD display panel comprises a plurality of pixel units formed of an EC material and an ECD pixel circuit for providing a driving voltage for the pixel units. Each pixel unit displays a colour under the action of the driving voltage. The colour display process can be a colour development process or a colour fading process. In the colour development process, the transmittance of the pixel unit is gradually lowered such that the displayed colour becomes darker gradually; to the contrary, in the colour fading process, the transmittance of the pixel unit is gradually increased such that the displayed colour becomes lighter gradually. By adjusting the switch of the pixel unit between the colour development process and the colour fading process, the ECD display panel is able to demonstrate a colourful display effect.
However, the voltage characteristic and capacitance characteristic of the ECD pixel circuit decide that when an ECD is driven by a conventional display driving method, a display panel may have a poor-quality display due to the change in the power supply voltage signal in the pixel circuit.